Four-spotted Chaser (Libellula quadrimaculata)
Dragonflies are a well known and fascinating order of insects; you will likely see plenty of them as you go out into the field in late summer, normally near water. They are more common in warmer parts of the world than in temperate areas like the UK and of the 5 300 named species world-wide, only 38 live and breed in Britain. They are conveniently divided up into two groups Anisoptera the true Dragonflies which rest with their wings out from their body in a cross shape and Zygopteran or Damselflies who hold their wings above their body. In this article when I say Dragonflies I will mean both Anisoptera and Zygoptera, but I will use these terms separately when talking about the individual groups. Dragonflies have strongly biting mouthparts and are active and aggressive carnivores, both as adults and as young (called nymphs), preying mostly on other insects. The adults have massively large eyes, often meeting at the top of the head in Anisopterans. These eyes may each contain as many as 30 000 individual lenses or ommatidia (your eyes have only one lens each). Because of this Dragonflies have exceptionally good eyesight and have been known to respond to stimuli from more than 40 feet away. They have very small and poorly developed antennae though. They have two pairs of almost equally sized long thin membranous wings; both pairs of wings usually have a stigma (a dark or coloured patch near the middle of the leading edge) and a mass of cross veins giving them the appearance of being a mesh. Unlike most insects, which either flap both pairs of wings in unison ( Bees and Butterflies), or only flap the hind pair ( Beetles), or only have one pair ( Flies), Dragonflies can flap or beat their wings independently. This means the front wings can be going down while the back ones are coming up. You can see this happening if you watch closely. Dragonflies are excellent fliers, particularly the Anisopterans and can loop-the-loop, hover and fly backwards quite easil
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Keywords: beds, boggy, conservation, distribution, entomology, fauna, habitat, insects, nature, odonata, odonatists, ponds, pools, reed, widespread, wildlife
